Spring is part of the recommended toolchain, and in fact Vaadin applications are by default Spring Boot applications.
Contexts and Dependency Injection (CDI) is a framework for injecting dependency objects in different contexts. It is part of the Java EE platform, but its purpose is similar to autowiring in Spring.
In addition to running Vaadin as an application in a web page, you can embed it in a web page which could be part of some other application.
OSGi is an open source specification that describes a modular system and a dynamic service platform for Java. Application and component bundles can be remotely installed, started, stopped, updated, and uninstalled without requiring a reboot.
Quarkus is an open source, Kubernetes-native Java framework made for Java virtual machines and native compilation. It optimizes Java specifically for containers, enabling it to become an effective platform for serverless, cloud, and Kubernetes environments.